<meta http-equiv="content-type" content="text/html; charset=utf-8">I&#39;m reading HtDP 29.3.<div><br></div><div>I get how value extraction from lists works in O(n) time, but how does extraction from structures work in O(1)?</div>

<div><br></div><div>Thanks (for being the &quot;help me with HtDP&quot; mailing list as well as the Racket mailing list...)</div><div><br></div><div>Luke</div>